Between 14 and 23% of the elderly receive a medication they should not have been prescribed. Up to 40% of patients do not take their medications as prescribed. Under-use of certain medications like beta blockers or ACE inhibitors is also of concern. Whereas clinical practice guidelines exist and departures from optimal practice are well-documented for specific diseases, it is not known whether such guidelines generalize to the elderly with multiple co-morbidities. In the limited clinical situations where clinical trial evidence of therapeutic benefit among the elderly is strong, barriers to guideline adherence are more prevalent in the elderly including drug-to-drug interactions, drug-disease contraindications, alterations in decision-making capacities, and compounded adverse event risk due to multiple medications. The University of Iowa Older Adults CERTs (UIOAC) offers the CERTs program research expertise for (1) making policy-relevant estimates of treatment effects and cost-effectiveness among subsets of the elderly defined by important characteristics such as function status, co-morbidity, and age and (2) identifying and designing interventions to address barriers to optimal therapeutics in the elderly in community care settings. Our collaborative spirit is indicated by our projects with community-based physician and pharmacist research networks and collaborations with state and federal funding agencies as well as end-users including health plans and a national chain pharmacy organization. The specific aims of the UIOAC are to: 1. Improve safety and effectiveness of medication use among older adults by a. A quasi-experimental intervention study of translating a collaborative model of hypertension management into community care of elderly patients. b. Three database studies and one prospective study of age disparities in chemotherapy treatments and function status, survival, and cost-effectiveness outcomes. c. A longitudinal survey of the effect of the Medicare Prescription Drug, Improvement, and Modernization Act (MMA) on patient medication safety and access. d. Three studies of age-related changes in patient decision making and their effect on health outcome. 2. Expand existing collaborations to new partnerships with private and public entities by a. A developmental project to formulate a structured procedure for identifying and resolving geriatric medication problems in the community with the goal of implementing the procedure in diverse public and private practice settings. 3. Educate providers, patients, and policy makers about therapeutic decision-making in the elderly.